The proposed studies are designed tovarify and build on preliminary evidence that all the self's acts of volition-choice, responsibility, initiative, self-regulation, controlled processing - draw on the same very limited resource, which is easily depleted by self-control or decision-making. Once depleted, this aspect of the self is then of ten unable or disinclined to cope with furthe demands or choices, and the results may include a passive reluctance to face up to decisions as well as broad failures of self-control. Passivity and self-control failure are central to many health and adjustment problems, including addiction, failure to take prescribed medication, procrastination, burnout, and binge eating. The first section of this proposal seeks to verify and extend preliminary evidence that self-control is a limited resources subject to depletion or fatigue. After people exert self-control, are they less able to control themselves in a second, seemingly unrelated sphere? Laboratory experiments will examine successive self-control exertions in unrelated spheres for evidence of fatigue or depletion. The second section moves from the relatively narrow focus on self-control to the broader concern with the self's choice-making activity in general. The key theoretical question is whether that limited resource used for self-control is the same resource or energy that the self uses for making all its decisions and choices, for initiating action, and for taking responsibility. If so, then that stock of energy is indeed one of the most central and important features of the self. The research plan is to show that active choice-making impairs subsequent self-control, and vice versa. The third section of the proposal addresses a key theoretical question surrounding this vital aspect of the self. Is the drop in self-control after an initial exertion due to a loss of motivation or of ability? Our model suggests that the self responds to depletion of its regulatory energy by trying to conserve what energy is left, even though it could make another exertion if necessary. Passivity and inaction may thus be strategic and even adaptive. The fourth section will explore several implications and applications of the depletion of self: vulnerability to loss of self-esteem from ego threat; prejudice; procrastination; and overeating.